Pinhole camera model with refraction correction for tomographic PIV inside cylinders

The present work addresses the development of a camera calibration model, based on the pinhole approximation and Snell’s law of refraction, for tomographic particle image velocimetry measurements inside transparent cylinders. Such a model adds to the pinhole-camera model parameters a relatively small number of parameters, which have an unambiguous geometrical or physical meaning. A calibration procedure for the innovative camera model is also outlined. Finally, the innovative model is comparatively assessed against the classical pinhole camera model and different polynomial-based models by using experimental data from an investigation of Rayleigh-Bénard convection.